Remove check-fast. Closes #4193, #8844, #6330, #7416
test: Ignore compile-fail/issue-5806.rs

Broken on BSD. #12460
mk: Pass the name of the make command to maketest.py

This should make BSD use the proper GNU make.
test: Ignore run-make tests that don't work on BSD
Ignore another test that fails mysteriously on BSD
Use ignore-freebsd for tests broken on FreeBSD
auto merge of #12304 : brson/rust/check-fast, r=alexcrichton